Science and technology news

Hand me a towel, it’s more hygienic

Posted onJune 10, 2013

Next time you wash your hands, it is worth remembering that it is more hygienic to dry your hands using paper towels than electric air dryers, according to a QUT-led study. Dr Cunrui (Ray) Huang’s research looked at the hygienic effectiveness of different hand drying methods in a bid to discover the best way to remove bacteria after washing your hands. “What I found was that from a hygiene viewpoint, paper towels are superior to electric air dryers,” Dr Huang said.

Dr Huang’s research reviewed 12 studies that evaluated the drying efficiency and removal of bacteria when using paper towels, cloth towels, hot air dryers and the new version of air drying, the jet air dryer.

“When looking at hygiene it is important to remember that the transmission of bacteria is more likely to occur from wet hands than from dry hands.

“A hand dryer takes 30 seconds longer to achieve about the same dryness as a towel and this is important because most people spend less than 20 seconds drying their hands in a washroom.

“One study found that after 15 seconds of drying with a towel the residual water on the hands was reduced to one per cent, whereas after 45 seconds under a hot air dryer the residual water was reduced to three per cent.”

Dr Huang said while wetness encouraged the survival and transmission of bacteria on the hands, the type of drying method also influenced the levels of bacteria left after hand washing.

He said there was a mixed view of the ability of hand-drying methods for removing bacteria but overall hot air dryers were found to be less effective than paper towel drying.

“It is likely that paper towels work better because they physically remove bacteria from the hands, whereas hot air dryers and jet air dryers can not,” he said.

“For centuries, hand washing has been considered the most important measure to reduce the burden of health care associated infections and the proper drying of hands is an essential component of effective hand hygiene procedures.

“Hand-drying effectiveness includes the speed of drying, degree of dryness, effective removal of bacteria and prevention of cross-contamination.”

Dr Huang said on the basis of this review, drying hands thoroughly with single-use, disposable paper towel was the preferred method of hand drying in terms of hand hygiene.

He said it was also the recommended method of drying in locations where hygiene was paramount such as hospitals and health clinics.